The director of Iran's Environment Protection Organization said on Sunday that the United Sates is the "worst" polluter in the world especially in producing greenhouse gases.

Kyoto Protocol participation map 2010
Green indicates countries that have ratified the treaty; Dark green are Annex I and II countries that have ratified the treaty; Grey is not yet decided; Brown is no intention of ratifying; Red is Canada, which announced its intention to withdraw in Dec 2011

Mohammad Javad Mohammadizadeh also said, "Today, in the destruction of environment we are faced with the silent death of people".

He added in the wars that have taken place in the world a great damage has been inflicted on the environment.

The United States not only is polluting the environment through waging wars in it is also killing people "silently" through emitting the biggest carbon dioxide, the environment official claimed.

"If hot bullets have targeted the chest of people of Afghanistan and Iraq many more silent bullets have targeted the American people and they are unaware of this," Mohammadizadeh noted.

The biggest emitters including the United States are mostly responsible for the climate change and its consequences including droughts.

Still some U.S. Republican politicians reject credible scientific studies that man-made emissions are to blame for global warming.

United Nations' climate talks in South Africa last year agreed to extend the Kyoto Protocol for five or eight years from 2013 into a second commitment period and to get all countries in 2015 to sign a new deal that would force them to cut emissions no later than 2020.

Unfortunately, the United States has never had a Kyoto target.

After Barack Obama was elected president four years ago the world expected the U.S. sign the Kyoto Protocol. However, this did not happen.

U.S. Congressmen have been indifferent toward the devastating effects of global warming for other nations, arguing that reducing greenhouse gas emissions would hurt the U.S. economy.

According to Western media, U.S. Senate lawmakers and the Obama administration have stiffened their opposition to a European law that targets emissions from commercial jetliners.

But contrary to what Mohammadizadeh claims, the UN data show China is now the biggest emitter of carbon dioxide (CO2) in the world.

The International Energy Agency announced in late May that China spurred a jump in global carbon dioxide emissions to their highest ever recorded level in 2011, offsetting falls in the U.S. and Europe.

CO2 emissions rose by 3.2 % last year to 31.6 billion tons, preliminary estimates from the Paris-based IEA showed.

China made the largest contribution to the global rise, its emissions increasing by 9.3 percent, the body said, driven mainly by higher coal use.

"When I look at this data, the trend is perfectly in line with a temperature increase of 6 degrees Celsius (towards the end of this century), which would have devastating consequences for the planet," Fatih Birol, IEA's chief economist told Reuters.

Scientists say ensuring global average temperatures this century do not rise more than 2 degrees Celsius above pre-industrial levels is needed to limit devastating climate effects like crop failure and melting glaciers.

They believe that is only possible if emission levels are kept to around 44 billion tons of CO2 equivalent in 2020.